split i18n strings where there are 2 pluralizable variables

There is a problem with these pluralizable strings:

    user:
      one: "You're viewing only {{filtered_posts_count}} posts by a specific user."
      other: "You're viewing only {{filtered_posts_count}} posts made by {{count}} specific users."

Obviously, it has multiple issues, but the biggest one is that it can't be properly translated into languages where you need more than 2 plural versions. In Czech, we use 3 versions (count=1, count=2..4, count>=5).